Use webconfig-model.xml headerconfig for report title

We should use the configuration already present for the legacy webapp for the report page title. In the webconfig-model.xml excerpt below, this would be `` for `BioEntity` resulting in: **Cc_08923** *Cajanus cajan*[ICPL87119]

This is currently not exposed as a WS, so this requires work on the IM backend.

Thanks to @sammyjava for feedback.

```xml
<class className="org.intermine.model.bio.BioEntity">

<headerconfig>

<titles>

<title mainTitles="secondaryIdentifier|primaryIdentifier" numberOfMainTitlesToShow="1"
subTitles="*organism.name*|[strain.identifier]" />
</titles>

</headerconfig>

<fields>

<fieldconfig fieldExpr="primaryIdentifier" label="Identifier"/>

<fieldconfig fieldExpr="secondaryIdentifier" label="Short identifier"/>

<fieldconfig fieldExpr="name" label="Name"/>

<fieldconfig fieldExpr="organism.name" label="Organism" />

<fieldconfig fieldExpr="strain.identifier" label="Strain" />

</fields>

</class>
```